Various vehicle systems and industrial machinery have control units that house electronic control components within a case. In the context of a rail vehicle, a control unit may be located on a locomotive. The electronic control components held in the control unit may be processing components (e.g., central processing unit or CPU), input/output components, power control components, tractive and/or braking control components, heating and/or cooling control components, and the like. The electronic control components may include circuit boards and electronic devices electrically connected to the circuit boards. During operation, the electronic control components may generate significant heat within the case of the control unit. The heat may negatively affect operation of the electronic control components, and potentially may damage the electronic control components.
In order to dissipate heat away from the electronic control components, some known control units may direct an air stream through the case such that the flowing air absorbs heat through conduction before the air is exhausted out of the case. The flowing air may include dirt, debris, moisture, or other contaminants that may damage the electronic control components if the air contacts the electronic control components. For example, in a vehicle application, the air directed through the control unit may be ambient air from the environment that the vehicle system is traveling through. It may be cost prohibitive to sufficiently filter and condition the ambient air prior to directing the air through the control unit.